Well, there are several aspects to this topic. For one, yes pacifiers can cause bfing problems but that doesn't mean they definitely always will. I like to wait a few weeks until breastfeeding is well established and to see if I can tell a need for the paci.
If my babe is comfort nursing at night but sleeping poorly because of not really wanting milk I'd consider a paci (and am actually introducing one with my 3 weeks old now for this very reason). During the day I don't mind letting him suck on my finger, and that's what we do the first couple weeks instead of a paci, but for everyone's sleeps sake I'm ok with a paci at night.
All that said, using a paci won't guarantee better sleepers, necessarily. My three older kids all took a paci in varying degrees during the early months and they all had very different sleep habits. My oldest had loads of sleep issues, second slept like a dream, 3rd was sort of in the middle, but needed to go for walks around the house or the block with his dad in order to get back to sleep. There just are more factors to nighttime stuff than that one thing.
Shelley, mom to dd 5/19/01, ds 9/06/02, and ds 4/01/07. Lost babe 4/09